This core will be under the direction of Dr. Jay Skyler, who is the Co-P.I. of the Program Project, Co-Director of the Behavioral Medicine Research Center and professor of Medicine, Pediatrics and Psychology at the University of Miami. Several of the procedures proposed in the subprojects requiring close medical supervision (e.g., euglycemic clamp, isoproterenol/phenylephrine infusions, exercise stress tests). Therefore, Dr. Skyler's presence as Core leader will be an important element of this work, and be will supervise these procedures in Subcore 2 along with Dr. Jennifer Marks. Much of the proposed methodology ina the program project involves biomedical assessments using state of the art instrumentation (e.g. echocardiography, impedance cardiography, noninvasive estimates of autonomic function). Dr. Skyler will oversee the development and use of this technology in Subcore 1, which will be under the direction of Dr. Joachim Nagel. Because of his training as an endocrinologist, Dr. Skyler will also oversee the activities of Subcore 3 (Biochemistry), which will be directed day-to-day by Dr. Mahendra Kumar. All of the proposed Projects will utilize the resources in this core.